The mechanism was a legislative contrivance that simply replaced a "Commissioner" with a "Chief Commissioner." The point, though, was to get rid of Megan Latham by a sleight of hand.

It was a tawdry and disgraceful exercise, and now it is accomplished.

Premier Mike Baird railroaded Commissioner Latham out of her job for one reason: revenge.

He wanted her gone because she dared to expose corruption in the Liberal Party.

In August, Commissioner Latham released her report into Operation Spicer. This was the investigation into the NSW Liberal Party that found prohibited donations from property developers and envelopes stuffed full of cash being handed over in the back of a Bentley.

It was an expose that was staggering in its extent. It exposed a systematic culture of rorting inside the Liberal Party.

Unfortunately, because of technicality in the Election Funding Authority Act, no-one will face prosecution for what the ICAC uncovered.

The Premier refused to consider amending the Act, arguing that his friends had suffered enough. They had, he said, paid a "heavy price personally, professionally and from a family point of view".

With the rorting revealed, the NSW Electoral Commission withheld more than $4 million in public funding from the Liberal Party.

Then, just three months later, the Premier passed legislation to dismiss the Commissioner who had exposed it all. It was payback -- pure and simple.

When the Independent Commission Against Corruption inquired into corruption within the Labor Party, the ALP expelled all those who had done the wrong thing.

But when the ICAC investigated corruption within the Liberal Party, the Premier terminated the ICAC Commissioner.

Like a judge, an ICAC Commissioner should never be punished for doing their job. They should only ever be removed by the parliament for proven misbehaviour.

The Parliamentary Committee that considered the ICAC's structure never considered terminating the services of Megan Latham. It was never contemplated or discussed.

The public needs to be confident that the ICAC has the untrammelled ability to investigate and expose corruption wherever it may lurk.

This independence has been central to the ICAC's effectiveness since it was established in 1988. To maintain the public's confidence, it must have the independence to decide what it will investigate and how it will do so.

If it sees a need to investigate politicians, or the political party of the government of the day, it must be free to do so without fearing that its budget will be cut or that its staff will be sacked.

The ICAC was established in 1988 by Liberal Premier Nick Greiner, with the support of then Labor Opposition Leader Bob Carr. Since then it has operated with bipartisan support.

But this bipartisanship ended last week when Premier Baird terminated the Commissioner with extreme prejudice.